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Old 3rd February 2010, 11:36   #3031
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Thanks for the link Tsk. It was nice to know that the DOF extends to infinity with apertures like f/8 on a wide angle shot for a not-so-close subject. I think one need to further reduce the aperture only to cut light, or is there something else?

I think in Rudra's Punto shot, the subject was closer - may be less than 2 meters - so an aperture of f/8 is not extending to infinity - just a guess.

Last edited by clevermax : 3rd February 2010 at 11:43.
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Old 3rd February 2010, 11:44   #3032
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Quote:
Originally Posted by Rudra Sen View Post
But I have a mental block about anything less than 24/36. I cannot give you a logical reason as why.
Hmm, I thought the answer was obvious. All your lens behave differently on cropped sensor. Your 20mm lens becomes 32mm, 70-200mm becomes 112-320mm, etc. That can be irritating.

Last edited by Samurai : 3rd February 2010 at 11:46.
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Old 3rd February 2010, 11:49   #3033
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Quote:
Originally Posted by clevermax View Post
I think one need to further reduce the aperture only to cut light, or is there something else?
For sharper pictures?
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Old 3rd February 2010, 12:06   #3034
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Quote:
Originally Posted by clevermax View Post
Thanks for the link Tsk. It was nice to know that the DOF extends to infinity with apertures like f/8 on a wide angle shot for a not-so-close subject. I think one need to further reduce the aperture only to cut light, or is there something else?

I think in Rudra's Punto shot, the subject was closer - may be less than 2 meters - so an aperture of f/8 is not extending to infinity - just a guess.
Full frame cams have narrower DOF. The smaller the sensor, the deeper the DOF for same Focal length.
For punto, I think F-11 will give you DOF to infinity
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For sharper pictures?
Lens sweet spots are around F7.1-F10, below F7.1 or so softness sets in, and at F-16 like apertures, diffraction effects lead to loss of sharpness.
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Old 3rd February 2010, 12:31   #3035
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Originally Posted by tsk1979 View Post
Lens sweet spots are around F7.1-F10, below F7.1 or so softness sets in, and at F-16 like apertures, diffraction effects lead to loss of sharpness.
Doesn't that depend on the lens system? In 4/3 system, the sweet spot is in f/2.8 to f/5.6 range. It becomes softer at F/8 or above.
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Old 3rd February 2010, 12:35   #3036
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You shoot mostly at F16, so unless you are shooting at F1.8 20mm, the wider DOF of the Crop sensor won't really matter.
That is only when I shoot cars. And at times I do go up to f25 too. But thatís not enough. Even good optics tend to show fringing at edge lines. My 20mm block is exceptionally good in control fringing but at higher aperture it happens some time.
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Originally Posted by tsk1979
On an unrelated note, I see you shoot 20mm at F16? Why so. Why not use a F8 etc., which is the sweet spot for lens, and you are atleast 8 feet away from the subject, it will give you everything between 4.5 feet to infinity in focus
f8 is simply not enough for car shooting. Often f25 is not enough. Of course it depends a lot on the distance from subject to camera and size (length) of the car. To keep things in sharp focus and right perspective we need to go for focus stacking. Painful process but superbly effective. We need to shoot on manual focus mode at shift focus (as we go along) from front to back for every exposure. Whole set of varied frames go through PHOTO ACUTE for total sharpness.
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Originally Posted by tsk1979
I suggest, you atleast try to get your hands on 7D for a week or so, and see the image quality etc.
I donít know anybody using 7D here in Bangalore. I donít know if brand shops let you test their cameras like that in India. I also need to test controlled light shots with various reflectors for shadow tones and depth. Iím sure itís a great machine. My UK forum friends tell me that. But as you know my usage is not normal all the time.
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I think one need to further reduce the aperture only to cut light, or is there something else?
That something else is depth of field though in landscape kind of shooting such high aperture (f20 - f22 Ė f25 types) is not really needed. Or let me put it this way: You wonít be able to make out the differences between those apertures. This is strictly for wide angle lenses though.
Quote:
Originally Posted by clevermax
I think in Rudra's Punto shot, the subject was closer - may be less than 2 meters - so an aperture of f/8 is not extending to infinity I guess.
Correct. Even f16 is not sufficient here without PHOTO ACUTE.

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Originally Posted by Samurai View Post
Hmm, I thought the answer was obvious. All your lens behave differently on cropped sensor. Your 20mm lens becomes 32mm, 70-200mm becomes 112-320mm, etc. That can be irritating.
This is irritating for me. You know me well Sharath.
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Old 3rd February 2010, 12:40   #3037
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Doesn't that depend on the lens system? In 4/3 system, the sweet spot is in f/2.8 to f/5.6 range. It becomes softer at F/8 or above.
No, not on the system only. It depends upon
1. Pixel density(dependent upon system and MP)
2. Lens itself

For example, lets take a hypothetical lens which has a sweet spot at F14 and use it on 8MP full frame sensor, where the photosites are big.
Here at 14MP you will get the best MTF(resolution),
Now lets put the lens on a 18MP APS-C sensor. For such a sensor, diffraction effects will start setting in around F-8/F-9, so after those apertures, it will start trading off.
At F-14, the diffraction effect may overshadow the lens sharpness benefit, and you may get the best pic at around F10

For that reason, in case of third party lenses which work on full frame, the lens test on sites like photozone and dpreview do two tests, one on APS-C sensor, and another on crop bodies with higher pixel density.
Often the results are totally different, though lens is same.

In 4/3 also, you will see that the sweet spot changes lens to lens.
I think the small sensor system has sweet spot for most lenses around F5.6 or so, rather than F-8
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Old 3rd February 2010, 12:53   #3038
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f6.7 - f5.6 I would say.
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Old 3rd February 2010, 14:00   #3039
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After waiting and cross checking the prices over a month, I have finally ordered my Nikkor 35 mm f/1.8 G AF-S DX prime lens from Adorama for $199.95, added adorama blower to it for 8.95 and the UPS shipping 51.65, total 260.55, marked as gift. Excitement of waiting starts.
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Old 3rd February 2010, 14:13   #3040
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Quote:
Originally Posted by Rudra Sen View Post
f6.7 - f5.6 I would say.
Samurai's favorite lens seems to be best at F5.6 though , when wide open
Olympus Zuiko Digital ED 12-60mm 1:2.8-4.0 SWD Lens Review: 3. Test results: Digital Photography Review
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Old 3rd February 2010, 15:08   #3041
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Quote:
Originally Posted by tsk1979 View Post
5D MKII is a great camera. But why aversion to crop bodies.
Old man's lenses (esp his wide angle) are optimised to FF bodies.

Quote:
Originally Posted by Rudra Sen View Post
But I have a mental block about anything less than 24/36. I don't have any idea about 3rd party lenses.
1. Is this because beyond 24mm (36mm on APS-C) you see distortion? I used at 17-55/2.8 APS-C lens on a 40D (APsC body) and have not noticed anything out of the ordinary then again I dont shoot archtecture or the kind of close ups you do.

2. I am not happy with Tamron or Sigma. I have a friend who is quite happy with the ATX-Pro range (he uses Nikon) but he does complain that they dont focus as fast (atleast when compared to good Nikon lenses).

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Originally Posted by Rudra Sen View Post
I'm talking about 1Ds Mark IV (S for full frame). Unless they launch that as Mark V.
Oops. Senility.

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Originally Posted by Samurai View Post
Your 20mm lens becomes 32mm, 70-200mm becomes 112-320mm, etc. That can be irritating.
Actually I quite like the 70-200/2.8 on my 40D. It is the perfect range (100-300) for school sports.

Quote:
Originally Posted by Rudra Sen View Post
f8 is simply not enough for car shooting. Often f25 is not enough.We need to shoot on manual focus mode at shift focus (as we go along) from front to back for every exposure.
what did you do in the days before digital? Can this procedure be done on film?
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Old 3rd February 2010, 15:30   #3042
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Quote:
Originally Posted by navin View Post
1. Is this because beyond 24mm (36mm on APS-C) you see distortion? I used at 17-55/2.8 APS-C lens on a 40D (APsC body) and have not noticed anything out of the ordinary then again I dont shoot archtecture or the kind of close ups you do.
Navin, 24/36 here is the frame size in mm. I didn't mean focal length here.
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Originally Posted by navin
what did you do in the days before digital?
Very interesting question. Use minimum 6/7 format. Large format will compensate for large blowups with less magnification. Even better 4/5" view cameras. 8/12" was dream.
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Can this procedure be done on film?
Easy way out in todays context. Scan TP and follow the same process in comp. Without software, rely on your personal skill.
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Old 3rd February 2010, 16:24   #3043
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Hi Guys.

I know there is a DSLR thread, but it is too huge a thread and my question will probably get lost, and I need to take this decision most probably by the end of the week.

I am looking to buy a basic DSLR and am stuck between Nikon and Canons 3000 and 1000. I am a bit inclined towards the Nikon, but I want experts opinion on the same.

Some facts that I have at hand

Nikon: Cost: With VR Kit Rs 28,500 (Also includes training class, tripod, 2 GB card, carry case etc)

Canon: Cost: With Kit Rs 26,000 (Includes Class, 2 GB Card and Case)

A dealer at Croma electronics told me to go in for Canon, because apart from Canon specific lenses, I could also purchase some cheaper non-canon lenses for the same. However with Nikon, it is compatible only with Nikon lenses, hence in the longrun cost may go up very high


Appreciate your help on the same


Thanks

Hi All,

Thanks for the advice. Acutally the camera is for my wife and she is competely into photography. Though, till now she was using the digital cameras, we have now decided to upgrade to something better for more professional photographs

The focal lenght for now, I am looking at is 18-55 and then probably a 55-200 or 18-200

Both the cameras are 10 mega pixel
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Old 3rd February 2010, 16:44   #3044
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Quote:
Originally Posted by navin View Post
Old man's lenses (esp his wide angle) are optimised to FF bodies.
Agree on this part. His 20mm with be 32mm, so he will need a canon 10-22 or Tokona 11-16 F2.8 to get equivalent Focal length

Quote:
2. I am not happy with Tamron or Sigma. I have a friend who is quite happy with the ATX-Pro range (he uses Nikon) but he does complain that they dont focus as fast (atleast when compared to good Nikon lenses).
I do not know of many people happy with longer zooms when it comes to third party lenses, however the wide angles are fine. you rarely shoot action with a 11mm lens, and since half the universe is in focus above F5.6, focusing is not a challenge too!

I feel, if Rudra is given a 7D with a Tokina 11-16 and sent off to shoot cars for a week, he will return a convert, and gift me his entire gear in gratitude
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Old 3rd February 2010, 16:45   #3045
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Originally Posted by thedreamcatcher View Post
Hi All,

Thanks for the advice. Acutally the camera is for my wife and she is competely into photography. Though, till now she was using the digital cameras, we have now decided to upgrade to something better for more professional photographs

The focal lenght for now, I am looking at is 18-55 and then probably a 55-200 or 18-200

Both the cameras are 10 mega pixel
first of all Nikon also works with Sigma and Tamron lenses, but availability on nikon mount is less. Canon service center reach is better in India than Nikon.
The Canon 18-55 -IS + 55-250IS will make a good dual lens kit, and can be had for about 35000(including 2GB card, carry case etc., etc.,)
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